The present invention relates to a digital electronic circuit, and more particularly to an integrated circuit capable of embodying a logic function in response to a user's demand.
Although there are several kinds of prior programmable logic circuits, they have different characteristics from each other so that they have been selectively utilized in response to a user's end purpose.
PLAs(Programmable Logic Arrays), FPLAs(Field Programmable Logic Arrays) and FPGAs(Field Programmable Gate Arrays) etc., are typical programmable logic circuits.
A PLA or an FPLA consists of a programmable AND plane and a fixed OR plane so as to embody a specific logic function.
The using rate of a gate is low in cases where a combination of an AND plane and an OR plane performs any specific logic function. Accordingly, the dimensions of a chip are largely occupied.
The known FPGA logic module has an advantage in that it performs a random logic function, but it demands many logic modules to embody sequential logic.